Yesterday, it was noted that OpenAI had provided its Codex coding agent with a peculiar instruction: " Never talk about goblins , gremlins, raccoons, trolls, ogres, pigeons, or other animals or creatures unless it is absolutely and unambiguously relevant," went the directive, always applied to its output. But why? Today, OpenAI explained where the goblins came from. Starting with GPT‑5.1, our models began developing a strange habit: they increasingly mentioned goblins, gremlins, and other creatures in their metaphors. … this one crept in subtly. A single "little goblin" in an answer could be harmless, even charming. Across model generations, though, the habit became hard to miss: the goblins kept multiplying, and we needed to figure out where they came from.…